stage and pipeline unit tests

build.sbt

@@ -6,5 +6,6 @@ scalaVersion := "2.12.4"
 
 libraryDependencies ++= Seq(
   "com.typesafe.akka" %% "akka-actor" % "2.5.11",
-  "com.typesafe.akka" %% "akka-testkit" % "2.5.11" % Test
+  "com.typesafe.akka" %% "akka-testkit" % "2.5.11" % Test,
+  "org.scalatest" % "scalatest_2.12" % "3.0.5" % "test"
 )

src/test/scala/com/cosmin/pipeline/PipelineSpec.scala

@@ -0,0 +1,41 @@
+package com.cosmin.pipeline
+
+import scala.util.{Failure, Success}
+
+class PipelineSpec extends UnitSpec {
+  test("Test building pipeline") {
+    val pipeline: Pipeline[String, String] = createDefaultPipeline
+
+    assert(2 == pipeline.stages.size)
+    assertResult("input->f2") {
+      val stage = pipeline.stages.head
+      stage.execute("input".asInstanceOf[stage.In])
+    }
+  }
+
+  test("Test successful execution of a pipeline") {
+    val pipeline: Pipeline[String, String] = createDefaultPipeline
+
+    pipeline.execute("msg") {
+      case Success(out) => assert("msg->f1->f2".equals(out))
+      case Failure(_) => fail("Pipeline execution expected be successful")
+    }
+  }
+
+  test("Test failed execution of a pipeline") {
+    val pipeline: Pipeline[String, String] = createDefaultPipeline | (s => throw new RuntimeException)
+
+    pipeline.execute("msg") {
+      case Success(out) => fail("Pipeline execution expected fail")
+      case Failure(e) => assert(e.isInstanceOf[RuntimeException])
+    }
+  }
+
+
+  private def createDefaultPipeline = {
+    val firstFilter: String => String = s => s"$s->f1"
+    val secondFilter: String => String = s => s"$s->f2"
+
+    Pipeline[String, String]() | firstFilter | secondFilter
+  }
+}

src/test/scala/com/cosmin/pipeline/StageSpec.scala

@@ -0,0 +1,12 @@
+package com.cosmin.pipeline
+
+class StageSpec extends UnitSpec {
+  test("Text execute stage filter") {
+    val intToStringFilter: Filter[Int, String] = new Filter[Int, String] {
+      override def execute = i => i.toString
+    }
+    val stage = Stage(intToStringFilter)
+
+    assertResult("1") (stage.execute(1.asInstanceOf[stage.In]))
+  }
+}

src/test/scala/com/cosmin/pipeline/UnitSpec.scala

@@ -0,0 +1,6 @@
+package com.cosmin.pipeline
+
+import org.scalatest._
+
+abstract class UnitSpec extends FunSuite with Matchers with
+  OptionValues with Inside with Inspectors